Process of forming ophthalmic lenses.



UNITED STATES PATENT oFFICE.

LUCIAN W. BUGBEE, or SOUTHBRIDGE, MASSACHUSETTS, ASSIGNOB To AMERICAN OPTICAL COMPANY, or SOUTHBRIDGE, MASSACHUSETTS, A VOLUNTARY Asso- CIATIGN.

To all whom. t may concern:

Be it known that I, LUCIAN W. BUGBEE, a. citizen of the United States, residing at Southbridge, in the county of Worcester and State of ,Massachusetts have invented certain new and useful Improvements in Processes of Forming Ophthalmic Lenses, of which the following is a specification.

VMy invention relates to improvements in ophthalmic lenses and has particular reference to those forms of lenses formed from two or more pieces of glass.

The leading object of my invention is the provision of an improved process by which the said separate pieces of the lens may be readily and satisfactorily united.

A further object of my invention is the provision of an improved process of so uniting the lenses that there will be no bubbles or other defects present in the finished article, and yethaving the parts So connected that while held against accidental loosening they may be readily separated when desired.

Other objects and advantages of my improvement should be readily apparent by reference to the following specification, taken in connection withl the accompanying drawings, and it will be understood that I may make any variation from the specific step hereinafter mentioned within the scope ofthe appended claim without departing from or exceeding the spirit of my invention.

In the drawings: Figure I is a sectional view through one part of a lens which has been treated by my improved process. Fig.

II is a similar sectional view through the. other part of the lens. Fig. III is a .sectional view through the two parts after they have been jeined by the improved process. Fig. IV is a sectional'view through a lens blank and wafer before thesame are united after having been initially treatedby the improved process. Fig.V V is af Similar view through the blanks after having been united. Fig. VI is aA face View -of afcompleted lens.

As previously stated, my .invention relates to an improved process of uniting portions of an ophthalmic lens and is 'applicable for use with any form `of compound lens although more particularly designed and especially applicable in the formationv of bifocal lenses comprising a major portion and a segment or segments secured thereto.

ySpecification of Letters Patent.

PROCESS 0F FQRMING OPHTI-IALMIC LENSES.

Patented Sepe. 14., 1915.

Application led May 29, 1914. Serial No. 841,944.

Hitherto in the formation of lenses of this nature but two satisfactory methods have fused. Both .of these prior 'art forms embody certain disadvantages, in that with the cemented form washing the lenses in vhot water, or in some instances even the heat of the body would prove sufficient to loosen the wafer or segment portion when the Same was liable to falll'off. On the other hand, with the fused type-'of lenses the original expense .of construction is considerable, Since the blank must be especially fused with care and then ground on both sides to the correct curve. One of the great disadvantages here present is that the segment and major portions of the lens are inseparably united. Consequently should any correction however slight be required in the lens it is necessary to replace the entire lens rather than replace only the segment should the defect be in the .reading portion of the lens. My improved process eliminates both of these difficulties and provides for the ready construction or formation of an ophthalmic lens in which the two parts will bev same preferably heat them and while hot apply thereto a coating of a suitable securing material 3, such as a borate orl silicate compound, which will become liquid or plastic only at a high temperature, but which at the same time will melt or fuse at a considerably lower temperature than that at which the parts to be united will become plastic.

IVhile I have mentioned here that I may use a borate orsilicate compound, it will be understood that I do not wish to be limited `to a connecting medium embodying these general characteristics since a very soft glass having a low melting point may be used, and fused carbonate and certain chlorids or sultids may be made use of and 1 ployecl hold the parts, the particular material eming the`v-| seitialwzpatfof this invention.y-l`A Upon the raising of the temperature of the COIlnecting or joining materia-l to therefquiretl Vpoint to"re1nler the saine ,p'l'astie orv 'liquid, "certain".reaction necessarily takes place. united and the connecting material at the temperature necessary to'leep theconnecb ingninzitei'ial""in" a Iliquid or plastic state,

until the reaction lnisappai'ently ceasedg Y- until-'the reaction of the connecting material n,

is completed serves to prevent any undesir ablevcrystallization"' or" 'Y reactionary effectA upon placing of--tlle'parts together with the v material therebetween, the resultbeing that the material will unite with the surfaces to berjoi'ned'and will securely hold' the saine together.v 4-The parts' having been thusl unitedv I thenianneal the completed blank in a sui'tablefmanner,after'Which it is ready -;'fo1nfinisliing'into the completed lens.

Toi-separate the parts it is merelyf necessary to again'rel'heat the same t'o that 'temiperature which -will serve 4to soften th'econ'- neetingrmediumg between' 'theparts" wheny jury I, therefore, hold vthev parts r:to Ibe` dental separation thereof.

in presence of tno witnesses?- LUCIAN Boonen... 4

they may be readily separated )vithou inl n ""5ithe1""ai1`daifiieufluai'tfs',bstitgted 35 for either '"f" the others which is yunsatisfactory in .any particular.

I -Frointhefforegoing description itv ivlill'llie understood -pby those ,couver-sant with* the art'that by my new and improved rprocess 40 l am. able t'o'-satisfactorily unite the parts ofan ophthalmic lens in a most satisfactory 4manner while reducing to a miniinunh'tle liability of ydefects or errors in the lens'on parts when desired while preventing acci- I claim;A y ,y e" The processr'of forming an ophthalmic 5 vlens blank ,consisting vin 'Coating the two parts thereofwith a suitable uniting Inedium ivhose fusing pointis lowerthanrthat of the said parts, heating the partsvto the fusing point j, yof .said connecting medium,v ,55 'A continuing Ithe heating action until the com-1` 1 pletion of the reactionof theconnecting`- medium, placing theparts with thevcoatev portions thereofin close engagement, andannealing the completed blank.,x

In testimony,ivhereof'l vaffix my signature i laccount ofthe manner of grinding the parts (5 .and also making it possible to separate the 

